A surrogate method to identify the serotype specificity of rotaviruses was developed. The assay is based on hybridization of PCR generated DNA probes corresponding to hyperdivergent regions of the VP7 and VP4 rotavirus genes to RNAs extracted from test specimens and immobilized on nylon membranes. To generate the probes, specific primers are employed to selectively amplify regions of the VP4 or VP7 gene which are associated with neutralization specificity. The inclusion of P32-deoxy ATP in the PCR yields probes of high specific activity. We have developed probes corresponding to most of the 12 known VP7 serotypes and the five known gene 4 alleles and have employed these probes in an analysis of various collections of rotavirus field specimens.